Right now we have a host of probes and observatories that is on or buzzing around other planets and moons of our solar system. We want to create "cities" on Luna, Mars and Venus. Luna and Mars have similar qualities that may suggest similar solutions. Lava Tubes may provide a means of expanding human habitability on there rocky terrains. We need to send probes into these underground channels and map and investigate their structures. NASA, has helped in the creation of many a start ups in the field of space avionics, what we need are those who would design these exoplanetary cities. What would these cities be used for, and what would be the population. Then you have the problem of infrastructure.. Luna Gas and Energy, we light up the moon. Who would be responsible for providing clean potable water? What about water purification? What about food and sustainability? What about air? What about transportation? Would the first inhabitants be connected to the major universities and colleges , along with scientists from the major space agencies? I know there is talk about having a radio observatory on the "Dark" side of Luna. Regardless of the population of Luna would be in the next 500 years, The future is determined by what we do today, and we must decide if the fate of humanity is worth our investing in the human expansion into the other planets of the solar system. The future of humanity may be written underground, be it Earth, Luna or Mars.